[Distutils] Spec for the egg-info format

[Paul Moore]

Is there a good spec of the egg-info (directory) format anywhere? I've
found various bits, notably in the setuptools documentation, but I'm
trying to get the details clear:

- What files are mandatory?
- What format should files be in (specifically, line-ending format and
to an extent encoding)
- Should filenames in installed-files.txt be absolute or relative (and
if relative, then to what)?
- Directory name format is PACKAGE-VERSION-PYVERSION.egg-info,
correct? Always? What about platform-specific binaries? Do they need a
platform ID in there?

Also, what is the defined filename format for egg files and wininst
executables? Is that defined anywhere (it seems to be more or less
PACKAGE-VERSION-PYVERSION[-PLATFORM].egg for eggs, and
PACKAGE-VERSION[.PLATFORM][-PYVERSION].exe for wininst).

If necessary, I can read the code from distutils/setuptools, but there
seem to be odd variations on the cheeseshop, and I'd rather be sure
what's accepted than stick purely to what the tools generate. But if
what the tools generate is all that's going to be reliably accepted,
then great, I'll go with that.

My main interest is in what pip accepts, FWIW. (I'm trying to write a
pip-compatible binary file installer).

Paul.